Wifi stays on whilst sleeping

Hi,

I've got a week old Retina MacBook and seem to be having an issue that causes 6-7% of the battery to drain overnight whilst it is sleeping.

The Wifi doesn't switch off even whilst it is sleeping, and yes Powernap is turned off.

I wake up arrive at the MacBook and it will have lost around 6-7% of its battery power and notice that every time the Wifi has been on and it has received emails and Facebook notifications during the night. I've got a MacBook Air 13" too and this has never happened. Do you think there is something wrong with my MacBook or are other people experiencing the same thing?

Thanks.